Reader response: Pimavanserin: A novel therapeutic option for Parkinson disease psychosis

Hawkins and Berman¹ acknowledge limitations to current therapeutic approaches (including medication costs), but underestimate potential negative effects of Parkinson disease psychosis (PDP) on the patient, caregiver, and health care system. PDP may be a harbinger of increased risk of morbidity and mortality, as well as portend admittance to a long-term care facility; these factors ultimately correlate with a surmountable burden on the system and higher cost to the patient over time.

The authors suggest that pimavanserin should be used as a second-line agent to an initial trial of low-dose quetiapine. An efficacious low dose is unlikely, and even at a low dose quetiapine can cause harmful side effects.² Early use of pimavanserin may be more cost-effective and result in no worsening of motor functions and no reduction in dopaminergic agents.³ Atypical antipsychotics should be second line to pimavanserin when Parkinson disease dementia is not sufficiently controlled.

Pimavanserin should be used as a first-line agent for the treatment of PDP and treatment should be started at symptom onset since PDP progression can be unpredictable. We agree with the Food and Drug Administration's indication for the use of pimavanserin⁴ given its efficacy data and safety profile and considering the broad side effect profile of the alternative antipsychotic medications.

• © 2018 American Academy of Neurology